IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Potassium formate with Formic acid and Water

Components:
   (1) Potassium formate; KCHO2; [590-29-4]  NIST Chemistry WebBook for detail
   (2) Formic acid; CH2O2; [64-18-6]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Bianco, P.; Haladjian, J.; Sabbah, R., Bull. Soc. Chim. Fr. 7, 2301 (1969).

Variables:

   Concentration = Composition at 25 ºC

Prepared By:
   T. A. Ageyeva

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Solubility values in the KCHO2-CH2O2-H2O system at 25ºC.
Chemical1Mass Fraction w1100 * Mole Fraction1aChemical2Mass Fraction w2Mole Fraction2aChemical3Mass Fraction w3Mole Fraction3aSolid Phase(s)b
KCHO239.4124.96CH2O257.8666.97H2O  2.73  8.07A
KCHO239.7121.10CH2O255.0561.06H2O  5.2414.8A
KCHO239.4722.68CH2O252.1054.71H2O  8.4322.6A
KCHO239.9322.22CH2O249.5250.37H2O10.5527.41A
KCHO240.3018.69CH2O236.4130.87H2O23.2950.44A
KCHO240.9318.87CH2O235.1129.57H2O23.9651.56A
KCHO240.2517.46CH2O231.2224.76H2O28.5357.78A
KCHO242.3517.63CH2O225.0919.09H2O32.5663.28A
KCHO243.5017.82CH2O222.2316.64H2O34.2765.54A
KCHO247.2019.28CH2O217.2212.86H2O35.5867.86A
KCHO249.1820.46CH2O216.2212.33H2O34.6067.21A
KCHO252.5122.29CH2O213.5810.53H2O33.9167.18A
KCHO261.8027.89CH2O2  6.54  5.40H2O31.6666.71A
KCHO266.2131.55CH2O2  4.97  4.33H2O28.8264.12A
KCHO276.6443.96CH2O2  3.99  4.18H2O19.3751.86A + B
KCHO278.4044.66CH2O2  1.30  1.35 H2O20.3053.99B
Notes:
   a  These values were calculated by the compiler.
   b  The solid phases are: A = KCHO2•CH2O2; B = KCHO2.

Method/Apparatus/Procedure:
   The isothermal method was used. The potassium formate content was determined by potentiometric titration. The solid phase was identified by thermogravimetry and Schreinemakers method.

Source and Purity of Materials:
   a.r. grade KCHO2 was used as received. Commercial a.r. grade formic acid contained less than 2% water. Deionized water was used.

Estimated Errors:

   Temperature: The temperature was controlled to within ± 0.05 °C. For the solubility it was ± 1%.